Field of the Invention
The present invention relates to a member for electrophotography to be used in an electrophotographic apparatus and a method of producing the member, and to a process cartridge and an electrophotographic apparatus each including the member for electrophotography.
Description of the Related Art
In a member for electrophotography including an electroconductive layer to be used in a developing roller, a charging roller, a developer-regulating member, or a cleaning blade in an electrophotographic apparatus, the electric resistance value of the electroconductive layer needs to be controlled to from about 105Ω to about 109Ω. As an electroconductive agent to be used for controlling the electric resistance value of the electroconductive layer within the range, there is known an ionic electroconductive agent, such as a quaternary ammonium salt. An electroconductive layer that is made electroconductive by the ionic electroconductive agent can be reduced in unevenness of its electric resistance value resulting from the dispersion unevenness of the electroconductive agent as compared to an electroconductive layer that is made electroconductive by an electronic electroconductive agent including carbon black. Accordingly, in the developing roller, an image on a photosensitive member can be uniformly developed with a developer, and in the charging roller, the surface of the photosensitive member can be uniformly charged.
However, the ionic electroconductive agent has a migration property, and hence the ionic electroconductive agent is liable to move in the electroconductive layer to bleed to the surface of the member for electrophotography owing to its long-term use. As a result, the ionic electroconductive agent that has bled to the surface may adhere to the surface of, for example, the photosensitive member abutting with the member for electrophotography to reduce the quality of an electrophotographic image.
To cope with the problem, Japanese Patent Application Laid-Open No. H10-175264 describes an electroconductive member having the following characteristic. A polyurethane ionomer is incorporated into the electroconductive member to prevent the contamination of a body to be charged due to the bleeding of a migratory component. In addition, in Japanese Patent Application Laid-Open No. 2011-118113, the bleeding of an ionic electroconductive agent is suppressed by using an ionic liquid having 2 hydroxyl groups and fixing the ionic liquid in a urethane resin.
The present invention is directed to providing a member for electrophotography that is not reduced in charge-providing performance even by its long-term storage and use under a high-temperature and high-humidity environment, and is hence conducive to the formation of a high-quality electrophotographic image, and a method of producing the member.
The present invention is also directed to providing an electrophotographic image forming apparatus that can stably output a high-quality electrophotographic image and a process cartridge to be used in the apparatus.